I am sorry, but no.... we would never opt to put ourselves in that position that could financially ruin us just for a bigger house.
Foreclosure would never cross our minds as it would ruin your credit for good. Kiss anything else goodbye if you have foreclosure or bankrupcy for years. A great credit score is valuable to KEEP.
#1. You still have $700 on the old house to pay monthly, assuming you have a good renter and nothing goes wrong. Does that $700 you will be contributing monthly include all the taxes and insurance. Yes, you will have to provide insurance on the home because it is in your name. Renters would have to provide insurance on the contents. What is the renter is crappy and destroys something or worse... you find no renter.
#2. Consider the expenses of running a house? You'll be responsible for 2 not just 1 house for upkeep. It is expensive keeping a house in the proper order with upgrades and repairs. What happens if you need a new heating/cooling system in 1 or both homes?
#3. You won't be putting ANY money into savings? This means you cannont afford this move. Save no money, make no money.... what about retirement, college, home repairs, car repairs the unforseen expenses that pop up?
#4. If you cannot financially afford ALL expenses to maintain the 2 homes, with upkeep, insurance, taxes, save money for yourself and the what if's then you do not need to make this drastic financial move or you could be placing your future in financial ruin.
Remember, just because you "qualify" for something, does not mean it is a smart move.
Before you truly consider this, talk to your financial, tax and legal advisors and understand the HUGE risk you would be putting on yourselves. That would not be worth a larger house in my book. We are big time planners financially and we would never do anything like that. Think of Need vs Want.
Best wishes and I am sorry if I came across harsh, I certainly didn't mean to... the urgency in my tone was please, no don't do this.